Essential fatty acids (EFAs) cannot be manufactured by animals including humans and are required in human nutrition. There are two groups of essential fatty acids, omega-3 fatty acids and omega-6 fatty acids. Omega-3 fatty acids are found naturally in the oil of cold-water fish, such as mackerel, salmon, sardines, anchovies and tuna, or as extracted oil from plants, such as flaxseed, canola (rapeseed), or soybean. Examples of omega-3 fatty acids include docosahexaenoic acid (DHA), eicosapentenoic acid (EPA) and alpha linolenic acid. Omega-6 fatty acids are found in both animal and plant material. Plant sources include unprocessed, unheated vegetable oils such as corn, sunflower seed, safflower, soy, sesame, and cottonseed oils. They are also found in plant materials such as evening primrose, black current seeds and gooseberry oils as well as in raw nuts and seeds, legumes and leafy greens. Omega-6 fatty acids include linoleic acid and its derivatives, such as arachidonic acid (AA). There are also conjugated fatty acids such as conjugated linolenic acid (CLA).
Omega-3 fatty acids are linked to a wide variety of beneficial health effects in documented intervention studies as essential constituents of cells, especially brain cells, nerve cells, retina, adrenal glands, and reproductive cells. Long chain omega-3 polyunsaturates (PUFA's) such as DHA/EPA are thought to have health benefits for the heart, skin, immune system and help regulate inflammatory diseases, attention deficit disorders and infant development. There are also a number of new studies underway that suggest benefits in preventing Alzheimers', dementia, and colorectal cancers.
There have been a number of patents granted outlining the benefits from specific omega fatty acids present in food and/or supplements. Several patents have also been granted for the enrichment of foods that are normally low or deficient in omega 3/6 and PUFA's. For example, U.S. Pat. No. 5,932,257 (Wright et al.) relates to DHA being produced in cow's milk through the feeding of cold-water fish meal to cows, using a feather meal based feed supplement. The feather meal used according to this prior art reference is used as an inhibitor of microbial degradation of DHA in the rumen of the dairy cattle. U.S. Pat. Nos. 4,911,944 and 5,290,573 also disclose the use of feed supplements containing fish meal combined with animal by-products eg. feather meal, bone meal and the like. A number of patents have also been granted for the elevation of omega-3 in eggs using flax meal or algae/DHA feed supplements in chickens.
A ruminant is an animal which possesses a complex stomach consisting of four morphologically distinct compartments. These compartments are rumen, reticulum, omasum and abomasum. The former two are derived from the terminal portion of the esophagus, and only the latter two are considered to be a genuine stomach. After passing through the first two compartments, the food is returned to the mouth. The rumen and the reticulum are fermentation compartments wherein Ophryoscolex Diplodinium and Plectridium cellulolyticum are commensal, and the digestion of the feed (vegetable tissues) is conducted by cellulase, amylase, or cellobiose secreted by these microorganisms (digestive symbiosis).
In ruminant animals such as cattle or sheep, there is a problem that occurs when a biologically active substance is, for instance, orally administered. Part of the substance may be decomposed by microorganisms in the rumen producing products such as ammonia or carbon dioxide gas. This partial decomposition makes it difficult or impossible for the animal to effectively utilize all of the administered proteins, amino acids or fatty acids contained in the active substance. Thus, a ruminant only receives the benefit of a portion of the nutrients fed to it and loses a portion for the support and formation of rumen microorganisms. While the nutrients contained in feed clearly contribute to the ruminant's sustenance, another source of nutrition for ruminants is the protein derived from those microorganisms in the rumen which are passed to the lower stomachs. Accordingly, it is important to maintain the microorganism population in the rumen in order to provide a constant source of this protein.
When special nutrients or drugs which must be absorbed or metabolized are administered to ruminants it is important to protect these substances from the environmental conditions of the first stomach: i.e., from the decomposition by microorganisms and from the influence of weakly acidic or weakly alkaline pH, so that the substance can be maintained intact until it reaches the intended digestive or absorptive site. Namely, it is desirable that certain nutrients and drugs pass through the rumen to the omasum without being affected by microorganisms, with digestion being conducted in the abomasum and the digested feed being absorbed by the small intestine. As noted above with U.S. Pat. No. 5,932,257, this was accomplished in part by including feathermeal as an inhibitor of microbial degradation of DHA within the composition. However, as noted above, this approach is not preferred, as the ruminant microorganisms are important and must be maintained. Other methods of protecting active components from degradation in the rumen have been described, e.g., in Canadian Patent application 2,147,432, which describes the use of hardened animal and plant oils and fats and fatty acid esters to protect the active ingredient. There are problems, however, encountered with this method, as it is often necessary to include within the active ingredient other special ingredients which will assist in the degradation of the ruminant bypass product, once the product has passed into the second and third stomachs for digestion. Thus, there is a need for a ruminant bypass ingredient which will assist in protecting essential fatty acids from attack by the microorganisms in the ruminant so that these fatty acids are available for use by the animal, once they have passed into the third and fourth stomaches of the ruminant complex stomach system.
Patents have also been granted for the elevation of omega-3 in eggs using flax meal or algae/DHA feed supplements in chickens. Flax in the case of most livestock feeds also acts as a laxative and can be a feeding deterrent. While flax seed is an excellent source of alpha linolenic acid, i.e. in the order of 15 g/100 g, whole flax seed passes through the body almost entirely unconverted; ground flax seed on the other hand rapidly losses its alpha linolenic acid content and does not store well in terms of linolenic acid content. In terms of algae (DHA fermented concentrates), these feed and food mixes are produced via genetic recombination technology, which has limited consumer favour in most markets.
Prior art feed formulas have a number of deficiencies on a practical basis. For example, fish meal/feather meal feed supplements are very unpalatable and can be a feeding deterrent to livestock such as cows, and only limited amounts of DHA can be achieved in the milk. Also, the use of animal by-products, i.e., blood meal/feather meal, have been banned in most countries to prevent the spread of infectious diseases. Moreover, obtaining elevated levels of beneficial compounds such as omega 3 fatty acids in meat or livestock by-products (milk, and milk processed products such as cheese, cream and the like), has been difficult to achieve. As noted above, this may be due to stomach physiology of livestock animals. For example, the rumen in dairy cows, breaks down long chain polyunsaturates eg. DHA/EPA, thereby preventing the elevation of natural sources/PUFA's in livestock, livestock by-products (eg. milk) or processed fractions. Thus, there is also a need to provide a food supplement that addresses the flavour and stability problems of prior art supplements.
It has also been documented that many food products for example, whole milk, and processed dairy products, meats, etc. contain omega 3/6's ratios of 1:5 or higher. Most scientific data and the views of health experts including nutritionists suggest that the lower the total omega 6 value relative to the omega 3 value, the greater the health benefits associated with the food. North American diets in particular have been widely documented as having higher (less healthy) omega 6 (polysaturated fatty acids) vs. omega 3 polyunsaturated fatty acids. Omega 3/6 ratios above 1:7 are of particular concern and may contribute to heart disease, circular disorders, and other health problems.
It has been suggested that consumption of certain grasses by livestock may enhance the total amount of omega-3 fatty acids found in milk and processed by-products versus the amount of omega-3 fatty acids found in conventional livestock fed silage feeds. However, relatively high levels of omega-3 fatty acids, usually in the form of alpha linolenic acid usually results in relatively low levels of DHA/EPA in milk. This is believed due to the low conversion rate of plant based (sourced) omega-3 fatty acids, for example alpha linolenic acid (ALA) into DHA/EPA.
There is a need in the art for feed supplements capable of elevating the amount of omega-3 fatty acids in milk and/or other animal by-products such as meat, etc. There is also a need in the art for feed supplements that are capable of protecting omega-3 containing plant based material from being prematurely digested before reaching the proper absorptive site of the digestive tract of an animal. Further, there is a need in the art for feeds and feed supplements that act synergistically to complement the total amount of DHA/EPA being converted or absorbed from the plants into the animal relative to other fatty acids such as omega-6 fatty acids.
The present invention overcomes drawbacks in the prior art. The drawbacks are overcome by a combination of the features of the main claims. The sub-claims disclose further advantageous embodiments of the invention and may also overcome drawbacks in the prior art.